Introduce yourself as someone who speaks with a stutter, and may sometimes pause, repeat, etc. Use a neutral or happy tone, and immediately mention something else neutral or fun, to reduce chance of your listener saying something (kind) but unhelpful. You are disclosing for yourself and there’s rarely anything you’d want a listener to do differently. Example for a kid at a playground “Hi, I’m Sally. Sometimes I stutter, and repeat my words or stop, like a frogs stuck in my throat. Hey, do you want to play tag?”